It will fit in any PCIE X16 (1.0,2.0,3.0) slot, but it is veerryy old. It launched/released in 2007 making it very weak to even the entry level cards of recent generations. It also is a DX9/10 card so it can't play most games that was released in the past few months or this year that are only DX11 compatible. It would heavily bottleneck the FX 9590 or any modern processor. The GTX 750Ti you had listed in the other thread is much better. Unless this is for a spare system to play some old games it won't be useful.
Also wrong section as you're asking about a GPU in the CPU section. I'm going to go look into the fans for your VRM in a second